Yes you can ‘stage’ the sending out of an email campaign to go out to a restricted number of contacts out of the total number of contacts to receive the email – this is done by using the ‘Restrict to’ option when you come to send out your campaign.

Please see a screenshot below to show the 'Restrict to' option:

For instance you may wish to send out an email campaign to a tag group with 300 contacts.  You can restrict the send to the first 30 contacts as shown above. 

Then you can send again to another 30 contacts by setting the 'Restrict to' setting again to ensure that your campaign is sent out in batches.   

Another way is to schedule the send – whereby you select a date and time for the email to be sent out - please click here to find out more information about using the 'Send later' option: